Work in this laboratory is devoted primarily to the study of the biochemical mechanisms of the chemotactic response of the polymorphonuclear leukocyte with special reference to its relation to the biochemical mechanisms of the other neutrophils functions, phagocytosis, and induced lysosomal enzyme secretion. In this project, one of the primary emphases is the investigation of the nature and mode of action of the activatable esterase or esterases of the cell. In this regard, the work on the isolation and purification of esterase 1 is being continued. The mechanism of the response of glycerinated polymorphonuclear leukocytes to ATP will be further explored to test further the hypothesis that the decrease in cell volume so obtained is a result of the interaction of the actomyosin-like system of the polymorphonuclear leukocyte. The study of the lysosomal enzyme secretion induced by chemotactic factors will be further explored, especially its relation to the chemotactic response induced by the same factors.